Hardware Description and Reference for Avaya ... - Avaya Support

Survivability
Avaya S8500 Media Server
Note:
Note: This section applies to all three models of the S8500 Media Server.
Recovery capability is embedded in the Communication Manager software that resides on the
S8500 Media Server. Thus, the S8500 Media Server can use the following recovery options:
RAM disk
● RAM disk on page 61
● Servers, port networks, and gateways that an S8500 ESS supports on page 61
● S8300 Media Server in an LSP mode on page 62
RAM disk is a portion of memory used as a disk partition. In the event of a hard disk failure, the
S8500 Media Server uses only RAM disk to provide call processing for up to 72 hours.
Administration and backups are prohibited.
S8500 Media Server as an Enterprise Survivable Server
A Communication Manager configuration may use the S8500 Media Server as an Enterprise
Survivable Server (ESS). The ESS option provides survivability to a configuration by allowing
backup servers to be placed in various locations in the customer’s network. An ESS assumes
call processing control of all or part of the configuration in case the main server, either an S8500
or S8700-series Media Server, fails or network connections to the main server fail.
A main server may have many, up to 63, ESSs available to provide backup service. The
placement of the ESS or ESSs in the configuration is typically targeted at ensuring that port
networks that are configured in different segments of the customer’s LAN/WAN can receive
service even when LAN/WAN connections are lost.
Once the communication failure to the main server has been corrected, control of call
processing may be returned from the ESS to the main server either manually port network by
port network or automatically for all port networks at once.
Note: In
Note:
the transition of control from the main server to an ESS, all calls are dropped
while the media gateways carrying the calls reset to connect to the ESS.
Servers, port networks, and gateways that an S8500 ESS supports
An S8500 Media Server may serve as the ESS for either an S8500 or an S8700-series main
server. If the main server is a S8500 Media Server, any and all ESS servers in the configuration
must also be S8500 Media Servers. If the main server is an S8700-series Media Server with a
duplicated control network or both duplicated control and bearer networks, the S8500 ESS can
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